High School Physics

Plotting magnetic lines of force with plotting compass

In this post, let’s see how to plot magnetic lines of force with a plotting compass. A plotting compass is a small pivoted magnet in a glass case with non-magnetic metal walls.

plotting compass
Figure 1

Plotting Magnetic Lines of Force with Plotting Compass: step-by-step

  • Lay a bar magnet on a sheet of paper.
  • Trace around the magnet with a pencil.
  • Place the plotting compass at a point near the magnet.
  • Mark the direction that the compass needle points by drawing a dot. (figure 1.1)
  • Move the compass so that the back of the needle of the plotting compass is exactly over B, and mark the new position of the needle by a dot. (Figure 2)
  • Continue this process until the other pole of the bar magnet is reached. (Figure 3)
  • Join the dots to give one line of force and show its direction by putting an arrow on it. (figure 4)
  • Plot other lines by starting at different points around the magnet. (Figure 5)
Figure 1.1
Figure 2

Figure 3

Figure 4
Figure 5
Magnetic field lines around a bar magnet
See also  Find the magnetic field at a distance of 20 cm from a long, straight wire carrying a current of 10A.
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